BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600
Rev. 4, 23-Jun-99 1 (9)
Document Number 85011
N–Channel Dual Gate MOS-Fieldeffect Tetrode,
Depletion Mode
Electrostatic sensitive device.
Observe precautions for handling.
Applications
Input and mixer stages in UHF tuners.
Features
D
Integrated gate protection diodes
D
Low noise figure
D
Low feedback capacitance
D
High cross modulation performance
D
Low input capacitance
D
High AGC-range
D
High gain
13 579
21
43 94 9279
BF998 Marking: MO
Plastic case (SOT 143)
1 = Source, 2 = Drain, 3 = Gate 2, 4 = Gate 1
95 10831
21
43
94 9278
BF998R Marking: MOR
Plastic case (SOT 143R)
1 = Source, 2 = Drain, 3 = Gate 2, 4 = Gate 1
2
1
34
13 56613 654
BF998RW Marking: WMO
Plastic case (SOT 343R)
1 = Source, 2 = Drain, 3 = Gate 2, 4 = Gate 1
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600 Rev. 4, 23-Jun-99
2 (9) Document Number 85011
Absolute Maximum Ratings
Tamb = 25
_
C, unless otherwise specified
Parameter Test Conditions Symbol Value Unit
Drain - source voltage VDS 12 V
Drain current ID30 mA
Gate 1/Gate 2 - source peak current ±IG1/G2SM 10 mA
Gate 1/Gate 2 - source voltage ±VG1S/G2S 7 V
Total power dissipation Tamb ≤ 60
°
C Ptot 200 mW
Channel temperature TCh 150
°
C
Storage temperature range Tstg –65 to +150
°
C
Maximum Thermal Resistance
Tamb = 25
_
C, unless otherwise specified
Parameter Test Conditions Symbol Value Unit
Channel ambient on glass fibre printed board (25 x 20 x 1.5) mm3
plated with 35
m
m Cu RthChA 450 K/W
Electrical DC Characteristics
Tamb = 25
_
C, unless otherwise specified
Parameter Test Conditions Type Symbol Min Typ Max Unit
Drain - source
breakdown voltage ID = 10
m
A,
–VG1S = –VG2S = 4 V V(BR)DS 12 V
Gate 1 - source
breakdown voltage ±IG1S = 10 mA,
VG2S = VDS = 0 ±V(BR)G1SS 7 14 V
Gate 2 - source
breakdown voltage ±IG2S = 10 mA,
VG1S = VDS = 0 ±V(BR)G2SS 7 14 V
Gate 1 - source
leakage current ±VG1S = 5 V,
VG2S = VDS = 0 ±IG1SS 50 nA
Gate 2 - source
leakage current ±VG2S = 5 V,
VG1S = VDS = 0 ±IG2SS 50 nA
Drain current VDS = 8 V, VG1S = 0,
VG2S = 4 V BF998/BF998R/
BF998RW IDSS 4 18 mA
G2S
BF998A/BF998RA/
BF998RAW IDSS 4 10.5 mA
BF998B/BF998RB/
BF998RBW IDSS 9.5 18 mA
Gate 1 - source
cut-off voltage VDS = 8 V, VG2S = 4 V,
ID = 20
m
A–VG1S(OFF) 1.0 2.0 V
Gate 2 - source
cut-off voltage VDS = 8 V, VG1S = 0,
ID = 20
m
A–VG2S(OFF) 0.6 1.0 V
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600
Rev. 4, 23-Jun-99 3 (9)
Document Number 85011
Electrical AC Characteristics
VDS = 8 V, ID = 10 mA, VG2S = 4 V, f = 1 MHz , Tamb = 25
_
C, unless otherwise specified
Parameter Test Conditions Symbol Min Typ Max Unit
Forward transadmittance y21s21 24 mS
Gate 1 input capacitance Cissg1 2.1 2.5 pF
Gate 2 input capacitance VG1S = 0, VG2S = 4 V Cissg2 1.1 pF
Feedback capacitance Crss 25 fF
Output capacitance Coss 1.05 pF
Power gain GS = 2 mS, GL = 0.5 mS, f = 200 MHz Gps 28 dB
g
GS = 3,3 mS, GL = 1 mS, f = 800 MHz Gps 16.5 20 dB
AGC range VG2S = 4 to –2 V, f = 800 MHz
D
Gps 40 dB
Noise figure GS = 2 mS, GL = 0.5 mS, f = 200 MHz F 1.0 dB
g
GS = 3,3 mS, GL = 1 mS, f = 800 MHz F 1.5 dB
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600 Rev. 4, 23-Jun-99
4 (9) Document Number 85011
Typical Characteristics (Tamb = 25
_
C unless otherwise specified)
0
50
100
150
200
250
300
0 20 40 60 80 100 120 140 160
Tamb – Ambient Temperature ( °C )96 12159
P – Total Power Dissipation ( mW )
tot
Figure 1. Total Power Dissipation vs.
Ambient Temperature
0
5
10
15
20
25
30
0246810
VDS – Drain Source Voltage ( V )12812
I – Drain Current ( mA )
D
VG1S=0.6V
0.4V
0
–0.4V
0.2V
VG2S=4V
–0.2V
Figure 2. Drain Current vs. Drain Source Voltage
0
4
8
12
16
20
–0.8 –0.4 0.0 0.4 0.8 1.2
VG1S – Gate 1 Source Voltage ( V )12816
I – Drain Current ( mA )
D
6V
5V
4V
0
2V
1V
3V
VDS=8V
VG2S=–1V
Figure 3. Drain Current vs. Gate 1 Source Voltage
0
4
8
12
16
20
–0.6 –0.2 0.2 0.6 1.0 1.4
VG2S – Gate 2 Source Voltage ( V )12817
I – Drain Current ( mA )
D
0
2V
1V
3V
VDS=8V 5V
VG1S=–1V
4V
Figure 4. Drain Current vs. Gate 2 Source Voltage
0
0.5
1.0
1.5
2.0
2.5
3.0
–2 –1.5 –1.0 –0.5 0.0 0.5 1.0 1.5
VG1S – Gate 1 Source Voltage ( V )12863
C – Gate 1 Input Capacitance ( pF )
issg1
VDS=8V
VG2S=4V
f=1MHz
Figure 5. Gate 1 Input Capacitance vs.
Gate 1 Source Voltage
0
0.5
1.0
1.5
2.0
2.5
3.0
24681012
VDS – Drain Source Voltage ( V )12864
C – Output Capacitance ( pF )
oss
VG2S=4V
f=1MHz
Figure 6. Output Capacitance vs. Drain Source Voltage
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600
Rev. 4, 23-Jun-99 5 (9)
Document Number 85011
–50
–40
–30
–20
–10
0
10
–1 –0.5 0.0 0.5 1.0 1.5
VG1S – Gate 1 Source Voltage ( V )12818
S – Transducer Gain ( dB )
2
21
4V
0
2V
1V
3V
f=800MHz
–0.2V
VG2S=–0.8V
–0.4V
Figure 7. Transducer Gain vs. Gate 1 Source Voltage
0
4
8
12
16
20
24
28
32
0 4 8 1216202428
ID – Drain Current ( mA )12819
VDS=8V
f=1MHz VG2S=4V
2V
1V
0
3V
y – Forward Transadmittance ( mS )
21s
Figure 8. Forward Transadmittance vs. Drain Current
0
2
4
6
8
10
12
14
16
18
20
02468101214
Re (y11) ( mS )12820
Im ( y ) ( mS )
11
VDS=8V
VG2S=4V
ID=10mA
f=100...1300MHz
f=1300MHz
700MHz
400MHz
1000MHz
100MHz
Figure 9. Short Circuit Input Admittance
–40
–35
–30
–25
–20
–15
–10
–5
0
5
0 4 8 12 16 20 24 28 32
Re (y21) ( mS )12821
Im ( y ) ( mS )
21
VDS=8V
VG2S=4V
f=100...1300MHz
f=100MHz
1300MHz
1000MHz
400MHz
700MHz
ID=5mA
10mA
20mA
Figure 10. Short Circuit Forward Transfer Admittance
0
1
2
3
4
5
6
7
8
9
0 0.25 0.50 0.75 1.00 1.25 1.50
Re (y22) ( mS )12822
Im ( y ) ( mS )
22
VDS=15V
VG2S=4V
ID=10mA
f=100...1300MHz
f=1300MHz
1000MHz
400MHz
100MHz
700MHz
Figure 11. Short Circuit Output Admittance
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600 Rev. 4, 23-Jun-99
6 (9) Document Number 85011
VDS = 8 V, ID = 10 mA, VG2S = 4 V , Z0 = 50
W
S11
12 960
–j0.2
–j0.5
–j
–j2
–j5
0
j0.2
j0.5
j
j2
j5
1
ÁÁÁ
ÁÁÁ
0.2
ÁÁÁ
ÁÁÁ
0.5
ÁÁ
ÁÁ
1
ÁÁ
ÁÁ
2
ÁÁ
ÁÁ
5
1300MHz 1000
100
Figure 12. Input reflection coefficient
S21
12 962
0°
90°
180°
–90°
1 2
–150°
–120°–60°
–30°
120°
150°
60°
30°
1300MHz
100
400
700 1000
Figure 13. Forward transmission coefficient
S12
12 973
0°
90°
180°
–90°
0.08 0.16
–150°
–120°–60°
–30°
120°
150°
60°
30°
1300MHz
100
200
1200
Figure 14. Reverse transmission coefficient
S22
12 963
–j0.2
–j0.5
–j
–j2
–j5
0
j0.2
j0.5
j
j2
j5
1
ÁÁ
ÁÁ
0.2
ÁÁ
ÁÁ
0.5
ÁÁ
ÁÁ
1
ÁÁ
ÁÁ
2
ÁÁ
ÁÁ
5
1300MHz
100
Figure 15. Output reflection coefficient
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600
Rev. 4, 23-Jun-99 7 (9)
Document Number 85011
Dimensions of BF998 in mm
96 12240
Dimensions of BF998R in mm
96 12239
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600 Rev. 4, 23-Jun-99
8 (9) Document Number 85011
Dimensions of BF998RW in mm
96 12238
BF998/BF998R/BF998RW
Vishay Telefunken
www.vishay.de • FaxBack +1-408-970-5600
Rev. 4, 23-Jun-99 9 (9)
Document Number 85011
Ozone Depleting Substances Policy Statement
It is the policy of V ishay Semiconductor GmbH to
1. Meet all present and future national and international statutory requirements.
2. Regularly and continuously improve the performance of our products, processes, distribution and operating
systems with respect to their impact on the health and safety of our employees and the public, as well as their
impact on the environment.
It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as
ozone depleting substances (ODSs).
The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and
forbid their use within the next ten years. V arious national and international initiatives are pressing for an earlier ban
on these substances.
Vishay Semiconductor GmbH has been able to use its policy of continuous improvements to eliminate the use of
ODSs listed in the following documents.
1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively
2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental
Protection Agency (EPA) in the USA
3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively.
Vishay Semiconductor GmbH can certify that our semiconductors are not manufactured with ozone depleting
substances and do not contain such substances.
We reserve the right to make changes to improve technical design and may do so without further notice.
Parameters can vary in different applications. All operating parameters must be validated for each customer application
by the customer. Should the buyer use Vishay-Telefunken products for any unintended or unauthorized application, the
buyer shall indemnify Vishay-Telefunken against all claims, costs, damages, and expenses, arising out of, directly or
indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use.
Vishay Semiconductor GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany
Telephone: 49 (0)7131 67 2831, Fax number: 49 (0)7131 67 2423
